Using GPS in vehicles
From OpenStreetMap Wiki
- At the moment, ...
- ... using the GPS devices of vehicles can be complicated, precise and also dangerous.
- is using an additionally plugged-in version of a GPS only. The built-in versions, the topic of this page, do not yet comply with the requirements. It is to be expected that the producers of the GPS units (not the motor vehicle industry) will change their approach when enough pressure (such as through OSM) asks for different input-/output-solutions. Usually updating still is impossible unless one buys expensive new versions of the corresponding software. But, things start changing.
- is the precision, due to the combination of a fairly quickly reacting GPS AND the supportive signals from tire-movements.
- Negative/To be handled with caution
- is the decrease of attention while driving. If you are not video-filming the data displayed together with the street itself, responsible driving on regular roads becomes very difficult and dangerous,
- is even when the data collection is done by a second passenger. The speed necessary to write down the data from the display would be tremendously high; but ... (see Positive/precision). Larger streets often follow a straight course which might help in doing it anyway.
- IMPORTANT: Same as the detail of de-activating the snap-to-street choice on a GPS, the car's equipment does that automatically[**]. Since the average CPU in a plugged-in or built-in GPS unit inside a car lacks the required speed to calculate with high precision (and display at the same time), you should use the GPS data output ONLY, but not the track-following state/mode (the mode which you normally use that thing for). Only if you use the GPS data output, is the data precise enough and in sync with your current position!
- Semi-Permanent Installation of a dedicated GPS logger out of sight of the driver is safer. For example serial based GPS data loggers are available which can be attached to serial NMEA GPS mouse type receivers. These can be hidden out of view, say on the vehicle rear parcel shelf (useful if power is switched by the ignition switch – saving logger memory and battery). The data logger can then be removed and downloaded away from the vehicle in safety.
[**] Rights may/will be violated. / Also, there might be legal restrictions on the mere usage of a car GPS unit, even if you own it yourself, and it gets worse if the car is rented or leased.